headers_check fix: linux/ipx.h

fix the following 'make headers_check' warning:

  usr/include/linux/ipx.h:13: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

include/linux/ipx.h

 #ifndef _IPX_H_
 #define _IPX_H_
+#include <linux/types.h>
 #include <linux/sockios.h>
 #include <linux/socket.h>
 #define IPX_NODE_LEN	6